Grease gun



Mar. 20, 1923. 1,449,219.

J. B. DAVIS.

GREASE GUN.

FILED AUG.24, 1921.

INVENTOR ATTORNEYS Patented Mar. 26), 1223..

LMQZILQ UNHTED STATES PATENT @FFHCE.

JOHN B. DAVIS, F SPRINGFIELD, MASSACHUSETTS, ASSIGNOR T0 GILBERT 8t BARKER MANUFACTURING COMPANY, A CORPORATION OF MASSACHUSETTS.

GREASE GUN.

Application filed August 24, 1921. Serial No. 494,939.

To all whom it may concern Be it known that 1, JOHN B. DAVIS, a citizen of the United States, residing at Springfield, in the county of Hampden and State of Massachusetts, have invented new and useful Improvements in Grease Guns, of which the following is a specification.

The present invention relates to apparatus for dispensing grease or heavy oils and more particularly to portable grease guns for garage use.

The invention consists in the features of construction and in the combinations and arrangements of parts hereinafter described and claimed, the advantages of which will be apparent to those skilled in the art.

In the accompanying drawings illustrating the preferred embodiments of the invention:

Fig. 1 is a side elevational view of the improved grease gun, certain portions thereof being broken away for purposes of illustration; and

Fig. 2 is a fragmentaryflview, partially in front elevation and partially in section, of the apparatus shown in Fig. 1.

In the illustrated embodiment of the invention the grease to be dispensed is contained within a cylinder 4 comprising a tube or shell 5 the lower end of which is seated in a base 6 constituting the bottom of the cylinder. The base 6 is provided with wheels 7 adapting the apparatus to be conveniently moved from one place to another and feet 8 are formed thereon which, together with the wheels, normally serve to support the cylinder 4 in a vertical position. To rigidly hold the shell 5 in position on the base, a ring 10 is internally rabbetted to receive the upper end of the shell and this ring carries a plurality of depending tie-bolts 11, the lower extremities of which extend through openings in the marginal portion of the base and are threaded to receive nuts 12 which are tightened against the base to rigidly secure the ring in place. from the bottom of the cylinder 4 through an outlet passage 14 in the base 6, this passage leading from the central portion of the base and being adapted for connection with a flexible hose 15 by means of which the grease may be delivered directly to the parts to be lubricated.

The grease is dispensed by the action of The grease is discharged a plunger or piston 17 which is movable vertically in the cylinder 4:. The piston 17 is adapted to be forced downwardly above the mass of grease in the cylinder to cause the grease to be extruded through the outlet passage 14, and the piston may be raised to a position above the top of the cylinder, as shown in Fig. 2, and then,

swung to one side in order that the cylinder may be conveniently refilled when necessary. To these ends the piston 17 is" rig.- idly secured to the bottom of a rod or spindle '18 carried by a frame 20 which is supported above the top of the cylinder. The frame 20 is pivoted at one end for horizontal movement about a vertical post 21 which rises from the ring 10. The opposite end of the frame 20 is provided with an open-ended slot 22 for receiving the upper portion of a post 23 rising from the ring 10 at a point diametrically opposite the pivot post 21. The slot 22 is so arranged as to permit the frame 20 and the piston 17 carried thereby to swing toward one side when the cylinder is to be filled. When the piston is to be again introducedinto the cylinder, the frame 20 is swung until the inner end of the slot 22 is seated against the post 23, the piston then being positioned in Y registry with the cylinder. Suitable collars 24 on the posts 21 and 23 are arranged to support the weight of the frame and the parts mounted thereon. A wing-nut 25 is provided on the post 23 for securing the frame in operative .position. The frame 20 is constructed with upper and lower guideways 28 and 29 through which the piston rod 18 is adapted to slide freely, the upper guideway being supported by a suitable yoke 30 rising from the lower portion of the frame. The piston is raised and lowered by the rotation of a nut 32 which is screw-threaded upon the piston rod and confined between the guideways 28' and 29 so that it is incapable of vertical movement. The-nut 32 is rotated by means of intermeshing bevel gears 34 one of which may be formed integrally on the nut 32 while the other is secured to a horizontal crank-shaft 35 that is journaled in a bearing 36 at one side of the yoke 30. The

crank-shaft 35 is adapted to be turned by means of a crank 37 which, as shown, is connected with the crank-shaft through suitable ratchet mechanism 38.

' ameter than the piston disk 40 and the marginal portion of the packing ring is bent downwardly so that its lateral face may conform to the contour of the cylinder walls. To insure against possibility of leakage between the acking ring and the cylinder walls the ownturned marginal portion of the former is preferably pressed outwardly by means of an ex ansible ring or annular sprin such as in icated at 45. As shown, the c amping collar 43 is provided with an annular shoulder 46 for retaining the expansible ring in place, and a thin stiff washer 47 may be interposed between the packing ring 42 and the clamping collar 43 to prevent collapse of the packing ring on the upstroke of the piston.

By reasons of inherent resiliency of the packing ring 42, the downturned portion of the ring tends to return to its original fiat condition and thus to enlarge the efi'ective diameter of the piston, this bein a wellknown expedient for insuring a tight joint between the piston and the cylinder. In the present construction the tendency of the packing ring to straighten is considerably increased by the action of the .expansi'ble ring 45. When a piston of this type has been withdrawn from its cylinder it is usually diflicult to replace it therein on account of the expanded condition of the packing ring. In accordance with an important feature of the present invention the inner face of the ring 1O on the cylinder is chamfered ofi' to form an upwardly-flaring annular face 50 which engages the peripheral edge of the packing ring as the piston is being introduced into the cylinder and guides it inwardly until the external diameter of the packing ring has been reduced to that of the interior of the cylinder. It has been found in practice that the inclined. or beveled face 50 acts uniformly and reliably to guide or tuck in the expanded edge of the packing ring, thus enabling the piston to be replaced in the cylinder without the slightest difficulty.

In accordance with another feature of the invention, provision is made for preventing the entrance of dust or foreign matter into the cylinder above the piston. To this end, a circular cover 52 normally rests upon the ring 10, the periphery of the cover overlying somewhat the upper face of said ring adjacent the chamfered face 50. The cover 52 is provided with a central aperture 53 through which the piston rod extends.

The central portion of the cover 52, adjacent the opening 53, is curved as shown at 54, to provide a bell-shaped rim portion which functions to prevent the screw threads on the piston rod 18 from engaging the edge of the opening in the cover in such a way as to rotate the cover therewith and which olfsets any tendency of the cover to rise with the piston rod before the piston itself engages the cover. It will be seen that when the piston is retracted from the cylinder, the cover 52 will be lifted with the piston, thus automatically opening the cylinder, and as the piston descends in re-entering'the cylinder the cover is returned into engagement with the ring 10 to again close the cylinder.

The upper end of the piston rod 18 extends above the guideway 29 and is enclosed within a tubular housing 56 which is secured, at its lower end tothe yoke 30. In order that the grease may be measured as it is dispensed, a pointer 57 projects laterally from the upper portion of the piston rod 18, the pointer extending through a vertical slot 58 in the side wall of the housing 56 and cooperating with graduations upon a scale 59 on the outside of the housing, adjacent one vertical edge of the slot 58. The outer end of the pointer 57 may be bent or curved so that it will be substantially parallel to the graduations of the scale 59, and the graduations may be arranged to indicate units of volume such as quarts and fractional parts thereof. With this construction, the quantit of grease dispensed will be accurately indicated on the scale 59. The housing serves to protect the threaded piston rod from dirt and injury and contrib-- utes to the general neat appearance of the apparatus.

While it is preferred to employ the specific construction and arrangement of parts shown and described, it will be understood that such construction and arrangement is not essential except so far as specified in the claims and may be changed or modified without departing from the spirit of the invention.

The invention having been described, what is claimed is:

Claims:

1. A grease gun having, in combination, a base, a vertical grease cylinder mounted on said base, said cylinder being open at the top and having an outlet adjacent its lower end for discharge of the grease, a piston adapted to be introduced into the top of the grease cylinder and forced downwardly therein to dispense the grease and to be retracted from the cylinder to permit the latter to be refilled, a piston rod rising from the piston, a ring internally rabbetted to receive the upper end of the cylinder and having an inner surface above said rabbetted portion flush at its lower end with meagre the inner surface of the side Wall of the grease cylinder and flaring upwardly therefrom to the top of the ring to facilitate the introduction of the piston into the grease cylinder, tie-bolts extending between the ring and the base for securing the former in place, a frame surmounting said ring and having guideways for said piston rod, said frame being constructed and arranged to permit the piston to be retracted above the upper end of the grease cylinder, means carried by said frame for supporting the piston rod and actuating it to raise and lower the piston, and a cover for normally closing the top of the grease cylinder, the cover having a central aperture through which the v piston rod passes and the cover being adapted to rest upon the top of said ring while the piston is depressed within the cylinder, to

be engaged and lifted bodily by the piston as the latter is retracted from the cylinder, and to be lowered into closed position by the descent of the piston as the latter is introduced into the top of the cylinder.

2. A grease gun having, in combination, a vertical grease cylinder open at the top; and having an outlet adjacent the bottom thereof for the discharge of the grease, a

piston adapted to be introduced into the top of said cylinder and forced downwardly therein to dispense the grease and to be retracte'd from the cylinder to permit the latter to be filled, a piston rod, means for supporting the piston rod and actuating it to raise and lower the piston, a cover for normally closing the top of the cylinder, the cover having a central aperture through which the piston rod passes and the cover being adapted to close the top of the cylinder while the piston is depressed therein, to

be engaged and lifted bodily by the piston as the latter is retracted from the cylinder, and to be lowered into closed position by the descent of the piston as the latter is introduced into the top of the cylinder, and said cover having its central portion offset upwardly around said central aperture to provide a bell-shaped rim portion flaring down wardly from its small end and merging with the surrounding portion of the cover.

In testimony whereof I have affixed my signature.

JOHN B. DAVIS. 

